The Stovebolt Site Forums The Parking Lot Big Bolts Dual master with or without booster conversion

I know prob covered but can't find with search from my phone.

Have 50 2 ton I want to swap master out for dual chamber and considering using modern booster as well.
Unsure of hydro condition and not interested in rebuilding. Gonna be a working daily driver need off the shelf napa parts for future replacement.

Assuming I can use the vette dual disc master since have drums both ends. Will use same booster as my panel which was created before kits and uses 1971? Ford 1 ton dual chamber booster 7" under floor and has insane stopping power.
Gonna be hard to find a dual master with enough bore to move 1.25" worth of fluid. Maybe early 70's big truck?

Ideas?
Part numbers?
Pics?

Hy ccpanel, I'm having a bit of trouble following what you're asking us. You will use a 71 F@#d booster and a Corvette dual master cylinder. Are you asking us if the Corvette master cylinder is large enough in bore to do the job? If you do end up using a master cylinder for a Corvette remember they were designed to be used with a disc/disc brake setup, so you will need to install 10 p.s.i. residual pressure valves in the lines to your wheel cylinders.

ok,
I have a 51 chevy coe. with the original single pot master cylinder and hydrovac. The master cylinder has a 1 1/4 bore. I am going to remove the hydrovac. and install a hydroboost out of a p30 or mid 90s chevy truck. The Hydroboost has a dual bowl master cylinder. You can install the hydroboost anywhere. I am installing a clutch slave cylinder on the hydroboost. The clutch slave cylinder will be connected to the original single bowl master cylinder. here is a link to show you the idea
http://tdsideas.weebly.com/store/p1/Remote_Hydroboost_Mounting_Kit.html
note:
I may have to change the master cylinder to a 1 inch bore as if you have different bore sizes, your pedal will have a different feel. and i cannot find a clutch slave cylinder with a 1.25 inch bore but did find a few with a 1" bore. The point being, keep the same ratio from the pedal to the hydroboost. the dual bowl master cylinder will most likely have a different bore size.
Hope this helps
Chris

Sorry
found master out of early 70's chevy 1 ton van with #7200 rear dually axle.
meant for drum/drum and is 1.25 bore.
also meant to originally come with vac booster... but they are firewall booster of teh 15+" variety.

im trying to
1: has anyone done a dual diaphram booster and driven a bolt with it?
2: anyone know of an actual application with a dual diaphram 7" booster?

the one I used on my panel was installed in 1996 and I cant remember the application which the only words my FLAPS knows.(or roackauto.com)

thanks for wanting to help!

that looks real neat.

cant do it.
running original 235(splasher not pressure) and will not be adding any type of hydro supply.

have to keep it vac.

also this will be a dailly working truck in teh hills of Oakland,CA... brakes mandatory.

Chris,
I really don't like that idea if there is any other way possible to have mechanical linkage to the booster and MC.
A major advnatage to upgrading to a dual circuit MC is safety, if one line blows you still have reasonable chance of stoping.
If you have the original MC operating the new one with a single line you have gained nothing for safety and added the complication of another hydraulic system to tend to.

That said I have done (in an old ford) exactly what you are considering. At the time I couldn't come up with any other options and afterward every time I drove the truck it bothered me, very mindful I could loose brakes at any moment.
https://picasaweb.google.com/lh/photo/HS0Ler0FXfwQyvaIaOoQEdMTjNZETYmyPJy0liipFm0?feat=directlink

Instead of that approach I don't know why you can't use linkage from original pedal back to the booster mounted in the frame?
Or if no room can even be done outside the frame. Pictures in this thread nicely illustrate some possibilities.
http://67-72chevytrucks.com/vboard/showthread.php?t=643079

Grigg,
You bring up a very good concern. I spent a lot of time reengineering and I will revisit what your saying.
I just received the parts now you got me thinking again.
Ill keep you informed.
Thanks
Chris

This has been brought up,time and time again,regardless of the make of the vintage trucks. With the single pot M.C.,it was designed for your truck's brake's application. When you "Up-grade" to a dual reservoir M.C.,there's a lot of engineering,and un-known variables involved. The hydrovac was designed to assist the system with over 2,000 P.S.I. does your hydroboost apply that much assist? The original M.C. had one bore,supplying both front and rear brakes with the Designated amount of pressure required,since rear brakes incorporated 2 wheel cylinders. When you change to dual M.C.,you're in un-chartered territory.you may have Good brake pedal,(correct play),but you may need to STAND on the pedal in order to MAYBE stop the truck,on LEVEL ground! The only Safe way ,(that I've heard of so far),is to swap the hydroboost,all the plumbing,and the brake wheel hardware,from a comparable G.V.W. "donor". Better SAFE,than SORRY! Good Luck!!

Check out this thread.. https://www.stovebolt.com/ubbthread...rake_conversion_on_a_46_.html#Post708681

mr willy,
Thats what I am doing,
I am duplicating a brake system the same as a 1980's p30/chevy 3500 series truck
I swapped the rear axle to the p30 dana 80 drw with disk brakes.I installed front disk brakes by changing the spindles(griggs idea & sticky) so the last step is to install the hydroboost w/ mc out of the same vehicle.
I was originally looking to activate the hydroboost with a clutch slave but will use linkage instead.

AWESOME Idea! If it's "Grigg Approved",I'll Bet Money on it! WELL-DONE!! I like the linkage idea! Sent you a P.M.

In my GMC 630, there is room under the floor to put a hydroboost in place of the original MC. Haven't figured out volumes yet. I saw an IHC w/ 466 and HB, so that might have more volume in it's HB, if needed.

Has anyone figured volumes? My 630 has dual slave cylinders, front and rear.